Traditionally, graphic images, audio, video, text and animations define the contents of a multimedia system. Recently, there has been significant progress in advanced multimedia systems incorporating virtual reality and haptics (or the sense of touch) into the human computer interaction paradigm. Haptics, a term that was derived from the Greek verb “haptesthai” meaning “to touch”, refers to the science of sensing and manipulation through touch. A haptic interface is a device which allows a user to interact with a computer by receiving tactile feedback.
The basic principle behind haptic interaction is simple: the user uses the handler of the haptic device to explore the virtual environment. At every time interval—say 1 millisecond—the computer checks for collisions between the simulated stylus and the virtual objects populating the virtual environment. If a collision occurs, the haptic rendering system computes the reaction forces and commands the actuators of the haptic device, thus leading to a tactual perception of the virtual objects. If no collision is detected, no forces will be applied and the user is free to move the stylus as if exploring the free space.
Haptics plays a prominent role in making virtual objects physically palpable in virtual and mixed reality environments. The incorporation of the sense of touch in multimedia applications gives rise to far more exciting and appealing ways of supporting collaboration, co-presence, and togetherness in multimedia systems by enabling users to feel each other's presence and the environments in which they are interacting. For instance, haptics is crucial for interpersonal communication as a means to express affection, intention or emotion; such as a handshake, a hug or physical contact.
One of the major challenges in haptic research is the communication of haptic data over a network, or what is usually referred to as tele-haptics. Tele-haptics pose new requirements and challenges at both the application level and the transport (networking) level. The haptic interaction requires simultaneous and interactive input and output by the haptic device with extremely high update rate (up to 1 kHz). At the application level, haptic interaction stability and transparency are the major concerns; especially stability since the device is applying physical forces that might hurt the users. At the networking level, quality of service parameters such as the network latency, jitter, and packet loss are key aspects.
Accordingly, systems and methods that enable synchronous interpersonal haptic communication through a network remain highly desirable.